As to wireless communication between a base station and a communication terminal device, at a time immediately after the start of the service, etc., in a wireless access network whose base stations are not yet sufficiently installed or in a service area having a low coverage on the population therein, the communication states of the communication terminal device in and out of a service area repeatedly alternate. As a result, a connection state and a disconnection state of a link layer often repeatedly alternate.
In an operation system (OS) operating on a personal computer (PC), etc., that includes a communicating function, an up and a down states of a logical interface (IF) alternate depending on a connection or a disconnection of the link layer. When the state of the logical IF transitions to the down state, all sockets opened toward the logical IF are closed and this closure seems to be a communication error of an application. Thereafter, even when the link layer is again connected and the state of the logical IF has transitioned to the up state, a procedure for a reconnection may be complicated.
As to such a wireless connection, it is known that: it is checked whether any service is being received when a time period set in an idle timer driven in an active mode has expired; and the active mode transitions to a virtual idol mode when a service is being received (Japanese Laid-Open Patent Publication No. 2008-182697).